The trend of vilifying carbs is hotter than the dot com boom and shows no signs of letting up. Yeah, and it’s totally wrong. Energy balance is the only thing that matters. You will lose weight if you burn more calories than you consume. That’s it. It’s the first law of thermodynamics. But notice, I said “weight” not “fat”. “Weight” could mean any combination of muscle and fat. I explained in part II of this series that the key factor involved in regulating the type of weight you lose (i.e. muscle vs. fat) is heavy resistance training in addition to an energy deficit. Technically, you could eat only Saltine crackers and still lose weight, and specifically fat.

Having a large proportion of your calories come from carbohydrates is really important while cutting because we know that it’s super important to keep lifting heavy and with a lot of effort during a cut. But remember, you’re going to be in an energy deficit, meaning that your capacity to move the weight will be diminished. The problem with cutting carbs while cutting is that your muscles will quickly become depleted of their favorite and most accessible fuel source, glycogen. If you reduce carbs, you reduce muscle glycogen and your capacity to move the weights right along with it. When lifting, if your body is depleted of glycogen, energy will come from fat. But fat and glycogen metabolism each occur through two mutually exclusive pathways. The bottom line is that the fat pathway doesn’t provide anywhere near the immediate energy that muscle glycogen pathway does. You will be at a real disadvantage if you rely on fat metabolism for the acute energy requirements of a set of heavy squats.

But what about the people who say carbs are different that the other two macronutrients (fat and protein) because they just somehow make you fat? There’s been a classic argument going on between Jillian Michaels (of Biggest Loser) and Gary Taubes (an anti-carb researcher); Jillian says carbs are just like any other food and losing fat is about energy balance, while Gary basically says carbs are the enemy. Check out this YouTube vid for some clips of the argument. The way I see it is that they’re talking right through one another and they’re both right. If you you eat lots of carbs, but accurately monitor your calories in and out and eat below your maintenance calories AND lift heavy, you will lose fat. I’ve done it many times while eating ice cream, cereal, fruit, potatoes, oatmeal and rice. So clearly this would indicate that Gary Taubes is wrong and Jillian Michaels is right, right? Yes and no. Taubes’ entire argument against carbs is based on the mechanism of autoregulation, whereby the body sends the appropriate satiety signals to the brain at the appropriate time. In essence, it’s the body’s natural “stop eating” signal. With a diet comprised of the right foods, this autoregulation mechanism works well, and people won’t become fat. I agree completely. Taubes says that when carbs–particularly foods made with refined cereal grains–are introduced into the diet, the autoregulation mechanism breaks because these foods create disproportionate insulin responses, which drives blood sugar through the floor and creates more hunger that is out of line with real energy requirements. That false hunger breeds more eating and potentially fat gain. I agree with all of this. I can feel this… like what happens to my body when I eat rice, which makes me hungry. I know this, but I like rice and I eat it with other stuff to buffer those effects and I also know what “false hunger” feels like and when to ignore it.

The point is that if you if you understand your body, if you understand how different foods work, if you calculate calories and maintain an energy balance, you can eat whatever food you want and override the autoregulatory inhibition that some carbs cause (although from the micronutrient standpoint, it’s not a good idea to eat refined foods). With the right carbs in your diet, you’ll have to do less overriding and more letting your body guide you.